Stent designed for the delivery of therapeutic substance or other agents

ABSTRACT

A stent comprising a serpentine portion extending about the circumference of the stent, the serpentine portion having a first end and a second end, the serpentine portion having a plurality of turns at the first end and a plurality of turns at the second end and struts extending therebetween, at least one of the turns at the first end, at least one of the turns at the second end, at least one of the struts therebetween, or some combination thereof having a plurality of shaped recesses thereon.

FIELD OF THE INVENTION

The present invention relates to a system for delivering substances intoa body.

BACKGROUND OF THE INVENTION

Stents are used for a variety of medical purposes in the body includingin the coronary arteries, the peripheral arteries, arteries of the neck,cerebral arteries, veins, biliary ducts, urethras, ureters, fallopiantubes, bronchial tubes, the trachea, the esophagus and the prostate.Stents are typically placed or implanted within a bodily vessel, forexample, for treating stenoses, strictures or aneurisms therein. Theyare implanted to reinforce collapsing, partially occluded, weakened, ordilated sections of a blood vessel.

Stents are typically available in self-expanding configuration andmechanically expandable configuration. Hybrid stents which areself-expanding in part and mechanically expandable in part are alsoavailable.

Many stents are manufactured with struts having a zig-zag or serpentineconfiguration which resembles that of a sine wave. An example of aserpentine portion of a stent is shown at 104 in FIG. 4 a. Serpentineportion 104 extends about the circumference of the stent and includes aplurality of turns 105 which extend between adjacent struts. Theindividual struts are oriented at an angle Θ₁ relative to longitudinalaxis 101 of the stent. When a stent comprising one or more of serpentineportions 104 is radially expanded from an unexpanded state to anexpanded state, as shown in FIG. 4 b, the angle Θ₂ of the strutsincreases relative to the longitudinal axis and the effective strutlength decreases from L to L-ΔL resulting in foreshortening of thestent.

Foreshortening of stents during deployment, however, is undesirable, asit reduces the placement accuracy of the stent. There remains a need forinnovative stents which do not foreshorten upon expansion.

Further, it is often desirable to deliver drugs into a patient's body totreat medical conditions. In particular, a variety of drug therapies areavailable for treating the coronary system, either alone or incombination with more invasive procedures. Such therapies may includedelivering substances, such as nitroglycerin, epinephrin, or lidocaine,endocardially or into the pericardial space to treat the coronarysystem. In addition, heparin, hirudin, ReoPro® or other anti-thromboticcompounds may be infused into blood vessels associated with the coronarysystem, such as occluded coronary arteries, or elsewhere in thecardiovascular system. More recently, gene therapy, e.g. introducinggenetic material, and growth factor therapy, e.g. introducing proteins,cells or vectors including angiogenic growth factors, have beendemonstrated to provide potential benefits in treating ischemic hearttissue and other regions of the coronary system, for example, bystimulating growth of neovascular conduits, which may evolve into newblood vessels.

Various methods have been used to introduce drugs into the vasculatureincluding, for instance, infusion catheters which may be optionallyequipped with either a porous perfusion balloon, and/or with anelectrode and/or heating element to improve localized delivery forcontinuous or intermittent delivery, ionophoresis in which a firstelectrode may be provided within a perfusion balloon, and a secondelectrode provided on an external region of the patient's body near theartery, embedding or depositing a drug on a catheter wall, a non-porousballoon wall on the catheter and/or a coating on the catheter, and soforth.

Another method of drug delivery has been to employ a stent. U.S. Pat.No. 6,258,121 describes, for example, a stent having a polymeric coatingfor controllably releasing an included active agent.

Without limiting the scope of the invention, a brief summary of theinvention is set forth below. Additional details of the summarizedembodiments of the invention and/or additional embodiments of theinvention may be found in the Detailed Description of the Inventionbelow.

BRIEF SUMMARY OF THE INVENTION

In one embodiment the present invention is directed to a stent having astrut with a first side and a second side, each side having alternatingcrests and troughs. The crests of the first side align with the troughsof the second side. The stent further has at least one adjacent strutwhich has a first side and a second side, each side having alternatingcrests and troughs. The crests of the first side of the adjacent strutalign with the troughs of the second side of the adjacent strut.Furthermore, the crests of the first side of the first strut align withthe crests of the second side of the adjacent strut and the troughs ofthe first side of the first strut align with the troughs of the secondside of the adjacent strut.

In one embodiment, the struts have a wave-like pattern.

In another embodiment, the struts have at least one shaped recessbetween the crest of a first side and the trough of a second side whichalign. Preferably, each aligning crest of the first side and trough ofthe second side will have a shaped recess as will the adjacent struts.The shaped recesses may be used to hold therapeutic agents which arethen delivered via the stent to the point of release. Desirably, shapedrecesses may be located between every crest of the first side and troughof the second side of the strut, as well as on adjacent struts. Thisparticular configuration allows for a maximum amount of drug deliverywithout sacrificing the strength of the stent.

The shaped recesses may be of any geometric shape or pattern and in someembodiments the shaped recesses are elongated ellipsoids orsubstantially circular shapes.

In another embodiment, the invention is directed to a stent comprising aserpentine portion extending about the circumference of the stent. Theserpentine portion has a first end with a plurality of turns and asecond end with a plurality of turns and struts extending therebetween.At least one of the turns at the first and second ends, and/or some ofthe struts of the serpentine portion have fully enclosed cut-out regionsextending therethrough, and/or have shaped recesses which do not extendall the way therethrough, but rather which are enclosed on three sidesand open on the top. The shaped recesses are smaller in dimension thaneither the turns or the struts.

Desirably, the stent comprises a plurality of serpentine portionsextending about the circumference of the stent, each of which has aplurality of turns at the first and second ends. At least some of theturns at the first end and at the second end of each serpentine portiondesirably have fully enclosed cut-out regions extending therethrough orshaped recesses which do not extend all the way therethrough. Moredesirably, each turn at each end of the serpentine portions has acut-out region extending therethrough and/or a shaped recess which doesnot extend all the way therethrough.

The inventive state may be provided in an embodiment having a proximalserpentine portion at a proximal end of the stent and a distalserpentine portion at a distal end of the stent where at least one anddesirably both of the proximal and distal serpentine portions have aplurality of turns with cut-out regions extending therethrough and/orshaped recesses thereon which do not extend all the way therethrough.

Some of the turns of the serpentine portions of the inventive stents mayhave cut-out regions and/or shaped recesses or all of the turns may havecut-out regions and/or shaped recesses. In one embodiment, every otherturn has a cut-out region and/or shaped recess.

In some embodiments, some or all of the struts may have shaped recessesthereon. Each strut may have one or more shaped recess thereon. In someembodiments some of the turns at the first and/or second end may alsohave shaped recesses. Each turn may have only one, or may have aplurality of shaped recesses thereon.

In accordance with the invention, the cut-out regions and/or struts mayassume a regular shape or an irregular shape.

In some embodiments of the invention, each turn having a cut-out regionand/or shaped recess therein comprises an inner turn having a firstwidth and an outer turn having a second width wider than the firstwidth. The cut-out region and/or shaped recess disposed between theinner turn and the outer turn. In other embodiments of the invention,each turn having a cut-out region and/or shaped recess therein comprisesan inner turn having a first width and an outer turn having a secondwidth wider narrower than the first width. In yet other embodiment, thefirst width is equal to the second width.

The inventive stents disclosed herein may be provided in embodiments inwhich the number of cut-out regions and/or shaped recess per serpentineportion varies along the length of the stent. Desirably, at least oneserpentine portion at one end and, more desirably, both ends of thestent will have more cut-out regions and/or shaped recesses than any ofthe serpentine portions in the intermediate section of the stent.

The inventive stents disclosed herein may also be provided inembodiments in which the size of the cut-out regions and/or shapedrecesses in the serpentine portions varies along the length of thestent. Desirably, at least one serpentine portion at one end and, moredesirably, both ends of the stent will have larger cut-out regionsand/or shaped recesses than any of the serpentine portions in theintermediate section of the stent.

In some embodiments, the invention is directed to a radially expandablestent comprising a plurality of serpentine portions extending about thecircumference of the stent, each serpentine portion having a pluralityof turns where at least some of the turns have fully enclosed cut-outregions extending therethrough. The cut-out regions are distributedabout the stent so that the stent opens in a non-uniform manner. In oneembodiment, the stent includes a proximal serpentine portion at aproximal end of the stent, a distal serpentine portion at a distal endof the stent and a middle portion disposed between the proximal anddistal ends of the stent and the cut-out regions are distributed suchthat one or both of the proximal and distal ends of the stent open priorto the middle portion of the stent. In another embodiment, the cut-outregions may be distributed such that the middle portion of the stentopens prior to one or both ends of the stent. The cut-out regions aretypically substantially arcuate prior to expansion of the stent althoughother shaped cut-out regions may also be employed. Desirably, each turnof each serpentine portion has a cut-out region. Optionally, in theseembodiments, shaped recesses for delivery of therapeutic agents may beprovided in combination with cut-out regions providing a stent thatopens in an non-uniform manner, and a stent that delivers a therapeuticsubstance.

The invention is further directed to a stent comprising at least onetubular serpentine member having a first end and a second end. Theserpentine member has a plurality of turns at the first end and aplurality of turns at the second end amd struts extending therebetween.In some embodiments, each of the turns at the first and second ends havea fully enclosed cut-out region extending therethrough. In someembodiments, each of the turns of the first and second ends and/or thestruts have shaped recesses thereon. Typically, the stent will comprisea plurality of tubular serpentine members with adjacent tubularserpentine members connected one to the other. Desirably, in thoseembodiments having fully enclosed cut-out regions, the shape of thefully enclosed cut-out regions changes as the stent is expanded. Moredesirably, the fully enclosed cut-out regions are characterized by afirst area when the stent is in an unexpanded configuration and by asecond area when the stent is in an expanded configuration, the secondarea larger than the first area.

The inventive stents may also be provided in embodiments in which thefully enclosed cut-out regions and/or shaped recesses are characterizedby a first width when the stent is in an unexpanded configuration and bya second width when the stent is in an expanded configuration, thesecond width greater than the first width. Typically, the cut-outregions and/or shaped recesses of the inventive stents will be arcuatewhen the stent is in the unexpanded state although cut-out regionsand/or shaped recesses of other shapes are also disclosed herein.

In another embodiment, the invention is directed to a stent comprising aserpentine portion extending about the circumference of the stent, theserpentine portion having a first end and a second end, the serpentineportion having a plurality of turns at the first end and a plurality ofturns at the second end and struts extending therebetween, at least oneof the turns at the first end, at least one of the turns at the secondend, at least one of the struts therebetween, or some combinationthereof have a plurality of shaped recesses thereon.

The shaped recesses may be of any geometry. In some embodiments, theshaped recesses are substantially circular, or are ellipsoids.

The invention is also directed to the combination of any of theinventive stent disclosed herein and a catheter. The stent has aproximal end and a distal end and a plurality of interconnectedserpentine bands including a serpentine band having a plurality ofcut-out regions and/or shaped recesses therein located on turns of theserpentine band or on the struts of the serpentine band. The stent isdisposed about a portion of the catheter and the retaining sleevedisposed about one of the proximal and distal ends of the stent. Theretaining sleeve is disposed about one or more serpentine bands havingcut-out regions and/or shaped recesses. The catheter may optionally beprovided with retaining sleeve at both the proximal and distal ends ofthe stent.

In some embodiments of the present invention, the stent is of a typicalstent geometry having connectors and struts forming the framework of thestent. The stent framework further has shaped recesses which provide areservoir for holding a substance or drug to be delivered within thebody of a patient. The shaped recesses may be of various configurationsor geometries, and may be of varying depth and size, i.e. width andlength or circumference. Furthermore, the number of shaped recesseslocated in the framework of the stent may also be varied. In thisembodiment, the stents are designed to deliver substances or drugs totarget locations within a person's body. More particularly, in someembodiments the stent is designed to deliver substances or drugs withinthe vasculature of a patient such as therapeutic agents including, butnot limited to, genetic material, growth factors, antineoplastics,antimitotics, anti-inflammatories, antiplatelets, anticoagulants,antifibrins, antithrombins, antiproliferatives, antibiotics,antioxidants, and antiallergenic substances, and so on and so forth, aswell as combinations thereof. The present invention allows thesubstances to be deposited directly at targeted locations within thebody or directly to selected tissue regions within the body.

The stents of the present invention may therefore have cut-outs, shapedrecesses, or some combination thereof, within the framework of thestents.

Additional details and/or embodiments of the invention are discussedbelow.

BRIEF DESCRIPTION OF THE DRAWING(S)

FIG. 1 a is a detail of a portion of a stent showing an embodiment ofthe strut configuration of the present invention.

FIG. 1 b is the same detail of a portion of the stent in FIG. 1 a in anexpanded state.

FIG. 1 c shows a portion of a stent having struts that do not includethe crests and troughs of the struts shown in FIGS. 1 a and 1 b.

FIG. 1 d shows the stent of FIG. 1 c having its struts replaced by thestruts of the stent shown in FIGS. 1 a and 1 b.

FIG. 2 a is an alternative embodiment of a detail of a portion of astent similar to that in FIG. 1 a having shaped recesses thereon.

FIG. 2 b is a detail of a portion of the stent structure as shown inFIG. 2 a in an expanded state.

FIG. 3 a is an alternative embodiment of the stent portion as shown inFIG. 2 a.

FIG. 3 b is the stent structure of FIG. 3 a shown in an expanded state.

FIG. 4 a shows a schematic representation of a serpentine band prior toexpansion.

FIG. 4 b shows a schematic representation of the serpentine band of FIG.4 a following expansion.

FIG. 5 a shows an inventive stent having shaped recesses in the flat.

FIG. 5 b is a sideview of a recess of FIG. 5 a.

FIG. 5 c shows an inventive stent having alternative shaped recesses inthe flat.

FIG. 5 d is a sideview of a recess of FIG. 5 c.

FIGS. 6 a–6 c shows an inventive stent having cut-outs in the flat.

FIGS. 7 a–7 c are enlargements of the circled region 4 of the stentsshown in FIGS. 6 a–6 c.

FIGS. 8 a–10 a show a portion of a serpentine portion of a stent in anunexpanded state, an expanded state and a crimped state, respectively.

FIGS. 8 b–10 b represent the same stent configuration as that in FIGS. 5a–7 a but with shaped recesses.

FIGS. 8 c–10 c represent the same stent configuration as that in FIGS. 5a–7 a but with alternative shaped recesses.

FIGS. 10 d–10 f illustrate the same stent configurations as in FIGS. 8a–10 c, above, but with shaped recesses of varying patterns, sizes andgeometries.

FIGS. 11 a–11 c and 12 show other inventive stents in the flat.

FIGS. 11 d–11 f shown alternative embodiments of the stents shown inFIGS. 11 a–11 c.

FIGS. 11 g–11 i show yet other embodiments of the stents of FIGS. 8 a–8f.

FIGS. 13–23 show other configurations of cut-out regions and/oroptionally shaped recesses.

FIGS. 24–26 show other inventive stents in the flat.

FIG. 27 shows an inventive combination of a catheter and a stent withcut-out regions and/or optionally shaped recesses.

DETAILED DESCRIPTION OF THE INVENTION

While this invention may be embodied in many different forms, there aredescribed in detail herein specific preferred embodiments of theinvention. This description is an exemplification of the principles ofthe invention and is not intended to limit the invention to theparticular embodiments illustrated.

For the purposes of this disclosure, like reference numerals in thefigures shall refer to like features unless otherwise indicated. Alsofor the purposes of this disclosure, the term “cut-out region” shallrefer to a region of a serpentine portion of a stent having an openingtherethrough, the opening surrounded by stent material. The term doesnot imply any particular method of forming a stent with cut-outs but,rather, refers to the absence of stent material in the region of thecut-out.

Further, for purposes of this disclosure, the term “shaped recess” shallrefer to a region of a serpentine portion of a stent which does not havean opening therethrough, but rather is a recess in the stent material ofvarying depth. The term shaped recess shall be used hereinafter toencompass those regions of the serpentine portion of a stent which arereservoirs which may be employed to hold substances such as therapeuticagents and which term may also be used to encompass those which could bedescribed as grooves, channels, slits, flutes, trenches, holes, and soon and so forth. The shaped recess may be of any geometry. Someparticular geometries include elongated ellipsoids, substantiallycircular recesses, oval, rectangular, square, triangular, and so on andso forth. Hereinafter, the term “substantially circular” shall be usedto include oval and so forth.

These shaped recesses are regions of the serpentine portion of a stentwhich are of varying depths and which do not extend all the waytherethrough. The term “stent material” as used above does not refer toany therapeutic agent which might be provided in the cut-out or shapedrecess of the present invention.

In general, this invention provides a radially expandable stent formedof any appropriate stent material including the shape memory alloys suchas the nickel-titanium shape memory alloys, for example NITINOL®, orstainless steel, for example. The stent includes a series of strutswhich act as circumferential segments circumscribing the cylindricalcontour of the stent. Each strut is alighend with a separate planeperpendicular to a central axis of the cylindrical contour of the stentand parallel to other planes to which adjacent struts are aligned. Thestent can have various different numbers of struts joined together toform the stent.

In one particular embodiment of the present invention, each strut has afirst side and a second side and each side has a series of bends whichhave troughs and crests alternating along the length of each strut. Thecrests of the first side of each strut align with the troughs of thesecond side of each strut.

The struts may be adjacent to one another. Each adjacent strut has afirst side and a second side, each side having a series of bends whichhave troughs and crests alternating along the length of each strut. Atrough of the first side of a strut will align with a trough of thesecond side of an adjacent strut and a crest of the first side of astrut will align with a crest of the second side of an adjacent strut.

The amplitude of each strut may be varied. Furthermore, the amplitudefrom strut to strut may be varied as well. The amplitude is defined bythe distance between the bottom of each trough and the top of each crestand is modified when the stent is radially expanded and the amplitude isdecreased.

Longitudinally adjacent struts may be connected to one another throughconnecting members. In various embodiments, the members aresubstantially linear, ushaped, v-shaped, s-shaped and so forth.

Turning now to the figures, FIG. 1 a illustrates an embodiment of thepresent invention. Strut 1 has first side a and second side b and strut2 has a first side a and a second side b. Additionally, each strut hascrests 10 and troughs 20. The crests 10 of first side a of strut 1 alignwith the troughs 20 of second side b of strut 1. The crests of secondside b of adjacent strut 2 align with the crests 10 of first side a ofstrut 1 and the troughs 20 of second side b of adjacent strut 2 alignwith the troughs 20 of first side a of adjacent strut 2. The amplitudeas noted above, may be varied.

FIG. 1 b illustrates the stent of FIG. 1 a in an expanded state.Additionally, connecting members 12 and 14 are shown betweenlongitudinally adjacent struts.

FIG. 1 c illustrates a different type of strut configuration in whichbands 15 and 17, for example, may be replaced with bands 13 and 14 a ofthe present invention, as shown in FIG. 1 d. Band 16 may also bereplaced with the innovative strut pattern of the present invention.Furthermore, any combination of bands 15, 16, and/or 17 may be replacedwith the strut pattern as described by the present invention.

FIG. 2 a illustrates an alternative embodiment of the present inventionin which substantially circular shaped recesses 30 are located betweenthe aligned crests 10 and troughs 20 on each strut 1,2. The shapedrecesses 30 are suitably employed for containing therapeutic agentsaccording to the present invention.

The quantity of the recesses employed on the stent, the size of therecess, and the depth, may all be varied in order to control the amountof a substance that is deposited into the body. The recesses assist inpreventing the substance from being disturbed during crimping, and allallow delivery of the substance to a target location without removal ofthe substance because it is located at a subsurface.

The above described embodiment results in a stent structure wherein therecesses are in a staggered pattern from strut to strut. This particularembodiment is desirable because it allows the maximization of thesurface area available for drug delivery, but without sacrificing theintegrity of the stent itself.

Substances which may be delivered in this fashion may include any drugsor substances which are desirably delivered into the body of a patient,particularly those which it may be desirable to deliver at a targetlocation in the body. Examples of such substances include, but are notlimited to, therapeutic agents including drugs and radioactivematerials. The term “therapeutic agents” as used herein includes, but isnot limited to, antithrombins; antiproliferatives; anesthetics;antifibrins, anticoagulants; antineoplastic/antiproliferative/antimioticagents; vascular cell growth promoters (i.e. proteins, cells or vectorsincluding angiogenic growth factors) including growth factor promoters,transcriptional activators and translational promoters; vascular cellgrowth inhibitors including growth factor inhibitors, growth factorreceptor antagonists, transcriptional repressors, translationalrepressors, replication inhibitors, inhibitory antibodies, antibodiesdirected against growth factors, bifunctional molecules consisting ofgrowth factor and cytotoxin, and bifunctional molecules consisting of anantibody and a cytotoxin; chlolesterol lowering agents; vasodilators;genetic material for gene therapy; platelet receptor antagonists;antiplatelet agents such as antiplatelet receptor antibodies;prostaglandin inhibitors; platelet inhibitors; tick antiplateletpeptides, antibodies; agents which interfere with endogenous vasoactivemechanisms; and so on and so forth.

Examples of antithrombins, anticoagulants, antiplatelets and antifibrinsinclude, but are not limited to, thrombin inhibitors such asANGIOMAX®from Biogen, Inc. in Cambridge, Mass.;D-phe-pro-arg-chloromethylketone (synthetic antithrombin); dextran;prostacyclin and prostacyclin analogues; sodium heparin; heparin andheparin derivatives; heparinoids; hirudin and recombinant hirudin;glycoprotein IIb/IIIa platelet membrane receptor antagonist antibody;prostacyclin and prostacyclin analogues; argatroban; forskolin;vapiprost; dipyridamole; urokinase, and PPack (dextrophenylalanineproline arginine cloromethylketone); RGC peptide-containing compound;platelet receptor antagonists; antithrombin antibodies; antiplateletreceptors; antibodies; aspirin; prostaglandin inhibitors; plateletinhibitors; tick antiplatelet peptides; and so forth.

Examples of cytostatic or antiproliferative agents include, but are notlimited to, enoxaprin, angiopeptin, angiotensin converting enzymeinhibitors such as captopril including CAPOTEN® and CAPOZIDE® availablefrom Bristol-Myers Squibb Co.; cilazapril or lisinopril such asPRINIVIL® and PRINIZIDE® available from Merck & Col. Inc. in WhitehouseStation, N.J.; calcium channel blockers such as nifedipine; colchicine;monoclonal antibodies capable of block smooth muscle cell proliferation,hirudin and recombinant hirudin, acetylsalicylic acid; fibroblast growthfactor (FGF) antagonists; fish oil (omega 3-fatty acid); histamineantagonists; lovastatin (an inhibitor of antifibrin and an inhibitor ofHMG-CoA reductase which is a cholesterol lowering drug available underthe tradename of MEVACOR® from Merck & Co. Inc.); the antithrombinsincluding sodium heparin, heparins and heparin derivatives, heparinoids,hirudin and recombinant hirudin, argatroban, forskolin, vapiprost,prostacyclin and prostacyclin analogues, dextran, dipyrimadole,D-phe-pro-arg-chloromethylketone (synthetic antithrombin), glcyoproteinIIb/IIIa platelet membrane receptor antagonist antibody, and so forth;thrombin inhibitors such as ANGIOMAX® from Biogen, Inc.; prostaglandininhibitor; serotonin blockers; steroids; thioprotease inhibitors; PDGFantagonists; nitric oxide; monoclonal antibodies such as those specificfor Platelet-Derived Growth Factor (PDGF) receptors; nitroprusside;phosphodiesterase inhibitors; suramin; serotonin blockers;triazolopyrimidine (a PDGF antagonist); and so forth.

Examples of anti-inflammatory agents include, but are not limited to,dexamethasone, prednisolone, corticosterone, budesonide, estrogen,sulfasalazine, mesalamine, and so forth.

Examples of antineoplastic/antiproliferative/antimiotic agents include,but are not limited to, paclitaxel such as TAXOL® Bristol-Myers SquibbCo. in Stamford, Conn.; docetaxel such as TAXOTERE® from Aventis S.A. inFrankfurt, Germany; methotrexate; azathioprine; vincristine;vinblastine; 5-fluorouracil; doxorubicin hydrochloride such asADRIAMYCIN® from Pharmacia & Upjohn in Peapack, N.J.; mitomycin such asMUTAMYCIN® from Bristol-Myers Squibb Co. in Stamford, Conn.; cisplatin;epothilones; endostatin; angiostatin; thymidine kinase inhibitors; andso forth.

Examples of anesthetic agents include, but are not limited to,lidocaine, bupivacaine, ropivacaine, and so forth. An example of anantiallergenic agent is permirolast potassium. Another example of atherapeutic agent includes, but is not limited to, alpha-interferon.

Examples of genetic materials which may be deposited into a patient'sbody employing the stents of the present invention include, but are notlimited to, anti-sense DNA and RNA, and DNA coding for tRNA and rRNA,cell cycle inhibitors including CD inhibitors, thymidine kinase (TK) andother agents useful for interfering with cell proliferation, bonemorphogenic proteins (BMPs), and so forth.

Specific BMPs include, but are not limited to BMP-2, BMP-3, BMP-4,BMP-5, BMP-6 (Vgr-1), BMP-7 (OP-1), BMP-8, BMP-9, BMP-10, BMP-11,BMP-12, BMP-13, BMP-14, BMP-15, BMP-16, and so forth. Preferred for useare BMP-2, BMP-3, BMP-4, BMP-5, BMP-6 and BMP-7. These dimeric proteinsmay be provided as homodimers, heterodimers, or combinations thereof,and alone or in combination with other molecules such as those moleculescapable of inducing an upstream or downstream effect on a BMP. Forexample, “hedgehog” proteins or the DNA's which encode them may beemployed in combination with the BMPs.

Cells which may be deposited at a target site in a body may be of humanorigin (autologous or allogeneic) or may be from an animal source(xenogeneic), or they may be genetically engineered if so desired todeliver proteins of interest at the transplant site such as epithelialcells. The delivery media may be formulated as needed to maintain cellfunction and viability as is known to those of skill in the art.

Radioactive isotopes may also be used for prosthesis usage inradiotherapeutic procedures and include, but are not limited to,phosphoric acid (H₃P₃₂O₄), palladium (Pd¹⁰³), cesium (Cs¹³¹), iodine(I¹²⁵), and so forth.

The above lists are not exclusive and are intended for exemplarypurposes only. The preventative and treatment properties of therapeuticsubstances or other agents are well known to those of ordinary skill inthe art and as such, the above lists are simply provided by way ofexample, and are not intended to limit the scope of the presentinvention. Other therapeutic substances or other agents which are notlisted herein are equally applicable for use and are also known to thoseof skill in the art.

FIG. 2 b shows the same stent configuration of FIG. 2 a having thesubstantially circular shaped recesses 30 located between aligned crests10 and troughs 20 on each strut 1, 2 in an expanded state.

FIG. 3 a illustrates an alternative embodiment of the stentconfiguration described in FIG. 2 a in which the shaped recesses 30 areelongated ellipsoids. FIG. 3 b illustrates the same stent configurationin an expanded state.

In another embodiment of the present invention, the stent may comprise aplurality of serpentine portions which extend about the circumference ofthe stent. For purposes of this disclosure, the term serpentineencompasses, but is not limited to, zigzag. Thus, a serpentine patternencompasses, but is not limited to a pattern having sharp turns and apattern having gradual turns.

With reference to the figures, a stent comprising a plurality ofserpentine portions which extend about the circumference of the stent isshown generally at 100 in FIG. 6 a. Serpentine portions 104 include aplurality of turns 105 at the proximal and distal ends of the serpentineportions.

Serpentine portions 104 are connected one to the other via one or moreconnectors 112. As shown in FIG. 6 a, connectors 112 include curvedsections and struts. As used herein, the term “strut” shall be used toencompass both those struts which are straight in configuration, as wellas those having any other configuration including those which arecurvilinear. First end 112 a and second end 112 b of connectors 112 arecircumferentially offset from one another.

As shown in FIGS. 6 a–8 a, proximal end 106 of serpentine portions 104and distal end 108 of serpentine portions 104 are provided with cut-outregions 116. Typically, as shown in the figures, each turn at each endof each serpentine portion will be provided with a cut-out region.Cut-out regions 116 have substantially the same curvature as the turns105 of the bands themselves and define an inner turn 107 and an outerturn 109. Desirably, cut-out region 116 extends substantially along aradius of turn 105.

As shown in FIG. 8 a, the total longitudinal length of serpentineportion 104 is denoted by L and the longitudinal separation between theinner radii of the serpentine portion is denoted by L₁. The width of thecut-out portion, as defined by the maximum separation between inner turn107 and outer turn 109, is denoted by L₂.

Upon expansion of the stent, as shown in FIG. 9 a, the totallongitudinal length of the expanded serpentine portion 104, denoted byL′ is only slightly shorter than L. The decrease in longitudinalseparation between the inner radii of the expanded serpentine portion,denoted by L′₁, is at least partially offset by the increase in themaximum separation between inner turn 107 and outer turn 109, denoted byL′₂.

It may further be desirable to employ the stents of the presentinvention for delivering substances into the body of a patient,particularly those wherein it is desirable to deliver at a targetlocation within the body. FIG. 5 a illustrates generally at 100 atypical stent geometry, and 5 c illustrate generally at 100, a stenthaving connectors 112 and serpentine portions 104 forming the frameworkof the stent. Serpentine portion 104 w exhibits variable depth recesses30 of a substantially circular shape which provide a reservoir forholding a substance such as a therapeutic agent. FIG. 5 c represents thesame stent as shown in FIG. 5 a but the shaped recesses are representedby an elongated ellipsoid rather than a substantially circular shape. Asideview of examples of a variable depth recess are shown at 103 inFIGS. 5 b and 5 d. As described above, the quantity of the recessesemployed on the stent, the size of the recess, and the depth, may all bevaried in order to control the amount of a substance that is depositedinto the body. The recesses assist in preventing the substance frombeing disturbed during crimping, and all allow delivery of the substanceto a target location without removal of the substance because it islocated at subsurface.

FIGS. 6 b to 9 b and 6 c to 9 c illustrate alternative embodiments of astent but having a geometry similar to the stents of FIGS. 6 a–9 a. Inthese embodiments, the cut-out regions of FIGS. 6 a–9 a, however, havebeen replaced with shaped recesses instead for delivery of a substancesuch as a therapeutic agent to a target location in the body of apatient. It is desirable that the shaped recesses therefore do notextend all the way through the serpentine portion 104 of stent 100.

FIGS. 6 c, 7 c, 8 c and 9 c represent stents which have a plurality ofshaped recesses on both the turns 104 a and the struts 104 b of theserpentine portion 104.

FIG. 10 f is illustrate of an inventive stent of the present inventionhaving a plurality of shaped recesses on both the turns 104 a and thestruts 104 b of the serpentine portion 104. In this particularembodiment, the pattern of placement of the shaped recesses isirregular.

Further to the present invention, shaped recesses such as elongatedellipsoids and/or substantially circular recesses, or recesses of someother geometry may be provided on regions of the serpentine of the stentother than those shown in FIGS. 6 a–9 a. For example, in FIGS. 6 b–9 b,the elongated ellipsoids are found on the struts 104 b of serpentineportion 104, while in FIGS. 6 c–9 c, the substantially circular recessesare found on both the curved sections 104 a and the struts 104 b ofserpentine portion 104.

FIG. 10 a shows the stent having cut-out areas in the turns. FIG. 10 billustrates elongated ellipsoid shaped recesses on the stent strutemployed in combination with the cut-out regions in the turns. FIG. 10 cillustrates the stent structure having cut-out regions in the turns andsubstantially circular shaped recesses on the stent struts. FIG. 10 dillustrates shaped recesses of various geometries which may be employed.FIG. 10 e illustrates that the pattern may include both elongatedellipsoids and substantially circular recesses on the same stent, aswell as shaped recesses of different sizes. FIG. 10 f illustrates thatthe shaped recesses may be placed along the stent strut in an irregularpattern.

In the case of a balloon expandable stent where cut-outs are employed asshown in FIGS. 10 a–10 c, during crimping of the stent, the size ofcut-out region 116 decreases slightly and the spacing between inner turn107 and outer turn 109 narrows. The decrease size of the cut-out regionof the crimped stent compensates for the increase in length of the stentthat may occur during crimping of the stent.

While the above figures are exemplary of the inventive, stents, it isimportant to note that other serpentine patterns may be employed aswell. For example, the serpentine portions may have a constantcross-section along its length or may have a varying cross section alongits length. In the latter case, the width and/or thickness of theserpentine portion may be varied along the length of the serpentineportion.

As shown in FIG. 6 a–6 c, for example, adjacent serpentine portions 104are out of phase with one another. It is also within the scope of theinvention for adjacent serpentine portions to be in phase with oneanother. More generally, adjacent serpentine portions may be provided inany phase relationship including 90 degrees and 180 degrees out of phasewith one another.

Adjacent serpentine portions may be of the same frequency and/oramplitude or may be of different frequencies and/or amplitudes. Anexample of an inventive stent in which adjacent serpentine portions areof a different frequency and amplitude is shown generally at 100 in FIG.11 a. Serpentine portions 104 v, 104 x and 104 z are of a firstfrequency and amplitude and serpentine portions 104 w and 104 y are of asecond, higher frequency and smaller amplitude.

The stent of FIG. 11 b includes cut-out regions 116 on serpentine 104 v,104 x and 104 z of the first frequency and amplitude and serpentineportions 104 w and 104 y of the second, higher frequency and smalleramplitude. Alternatively, the cut-out regions 116 may instead beelongated ellipsoids which do not extend all the way through the stentmaterial.

Other shaped connectors may also be provided including substantiallystraight connectors, as shown in FIG. 11 a, connectors which are curvedand do not have any struts and connectors having one or more curvedsections and one or more struts. Also, the first and second ends of eachconnector may be circumferentially aligned with one another, as shown inFIG. 11 c, or circumferentially offset from one another as shown in FIG.6 a. An example of a linear connector whose first and seconds ends arecircumferentially offset from one another and also is non-parallel tothe longitudinal axis of the stent is shown in WO 9626689.

Each connector may have a constant cross-section along its length or mayhave a varying cross section along its length. In the latter case, thewidth and/or thickness of the connector may be varied along the lengthof the connector.

FIGS. 11 d–11 i illustrate the inventive stents of the type shown inFIGS. 11 a–11 c but the cut-out regions have been replaced with variousshaped recesses which act as reservoirs for holding substances such astherapeutic agents. FIG. 11 d illustrates an embodiment of the stentwherein elongated ellipsoid recesses are located along the struts 104 bof the serpentine portions. The elongated ellipsoid recesses are shownon serpentine portions 104 v and 104 z. However, other shaped recessesmay be located on any of the serpentines portions and in variouscombinations as will be illustrated by the following figures.

FIG. 11 e shows an alternative embodiment in which the recesses areshown in a more circular shape and are located on both the curvedsections 104 a and the struts 104 b of the serpentine portions. In thisembodiment, the recesses are shown on serpentine 104 x, but again may belocated on any of the serpentine portions.

Shown in FIG. 11 f is yet another alternative embodiment in which theshaped recesses include both elongated ellipsoids and substantiallycircular shaped recesses along the serpentine portions 104 v–104 z. Theelongated ellipsoids and substantially circular shaped recesses areshown on both the curved sections 104 a and the struts 104 b of theserpentine portions.

FIG. 11 g shows an alternative embodiment in which elongated ellipsoidshaped recesses are located along the struts 104 b of serpentineportions 104 v, 104 x and 104 z.

FIG. 11 h illustrates an alternative embodiment in which the shapedrecesses are triangular in shape and are located on the curved portions104 a of serpentine portions 104 w and 104 y.

FIG. 11 i illustrates another alternative embodiment in which the shapedrecesses are located along both the curved sections 104 a and the struts104 b of serpentine portions 104 v, 104 x and 104 z. The shaped recessesmay be of various geometrical shapes and patterns, and the placement ofthe shaped recesses may vary as well. Further, size and depth may bevaried as well.

The above figures are intended to be illustrative of only some of theshapes of the recessed areas and the patterns of placement on the stentand are not intended to limit the scope of the present invention. Thesefeatures may be employed in endless shapes and patterns withoutdeparting from the scope of the present invention, and thus the abovedescription should not be intended to limit the scope of the presentinvention.

The inventive stents may also be provided in embodiments in which thereis a one-to-one relationship between the number of turns in a serpentineportion and the number of connectors, as shown in FIG. 6 a, inembodiments in which there are fewer connectors than turns and inembodiments in which there are more connectors than turns.

An example of the former is shown in FIG. 12. Every other pair of turnsis connected in the stent of FIG. 12. The inventive stents may also beprovided with other regular and irregular spacings of the connectors.

Stents having cut-out regions or shaped recesses of varyingconfigurations or geometries in the regions of the turns are also withinthe scope of the invention, as are shaped recesses of variousconfigurations and geometries located in the regions of the struts ofthe serpentine portions.

Another example of an inventive cut-out region in a turn of a serpentineportion of a stent is shown in FIG. 13. Cut-out region 116 in turn 105is centered so that inner turn 107 is of the same width as outer turn109. Cut-out region 116 may also be located closer to the inner diameterof turn 105 as shown in FIG. 14, resulting in inner turn 107 having anarrower width than outer turn 109. In another embodiment, cut-outregion 116 is located closer to the outer diameter of turn 105 as shownin FIG. 15, resulting in inner turn 107 having a wider width than outerturn 109.

The size of cut-out region 116 may be altered to control the extent offoreshortening of the stent as well as to control the force needed toexpand the stent in the case of a balloon expandable stent. An exampleof a wide cut-out region is shown in FIG. 16.

In accordance with the invention, more than one cut-out region may beprovided in the vicinity of a turn. FIG. 17 a shows an embodiment of theinvention in which three circular cut-out regions 116 are provided inturn 105. Another embodiment of the invention in which multiple cut-outsare provided is shown in FIG. 17 d. More generally, any of the stentsdisclosed herein may comprise multiple cut-outs in the vicinity of theturns.

In many of the embodiments of the invention disclosed herein, the cutoutregions have a substantially arcuate appearance. Other shaped cut-outsmay also be provided. By way of example only, an elliptical cut-outregion having a major axis parallel to the longitudinal axis of thestent is shown at 116 in FIG. 17 b. An elliptical cut-out region havinga minor axis parallel to the longitudinal axis of the stent is shown at116 in FIG. 17 c. The presence of multiple elliptical cut-out regions inshown in FIG. 17 d.

The length of the cut-out region may also be adjusted in accordance withthe invention. For the cut-out regions in the turns of the serpentineportion, for example, a minimum length cut-out region 116 may be found,for example, in FIG. 17 a while a maximum length cut-out region 116 maybe found in FIG. 18, for example. Cut-out region 116 shown in FIG. 18extends along the entire length of the radiuses portion of turn 105. Itis noted that turn 105 includes a plurality of cut-out regions 116. Anyof the other embodiments of the invention may be modified to provide aplurality of cut-out regions per turn. For example, in those embodimentsof the invention in which the cut-out regions are arcuate, multiplearcuate regions may be provided.

It is also within the scope of the invention for the cut-out region tohave an irregular shape as shown in FIG. 19.

Where a connector extends from the turn, as shown in FIG. 20, cut-outregion 116 may optionally be limited to the region of turn 105corresponding to the longitudinal extension of connector 112. Connector112 of FIG. 20 extends from the inner turn 107 or inner diameter of turn105. An example of a larger cut-out region 116 which extends toward aconnector 112 extending from inner turn 107 is shown in FIG. 21.

FIG. 22 illustrates a larger cut-out region 116 which extends intoconnector 112. Connector 112 extends from inner turn 107. FIG. 23illustrates a larger cut-out region 116 which extends into connector 112which, in turn, extends from outer turn 109.

As in previous embodiments, the cut-out regions as illustrated in FIGS.13–23 may be replaced with recesses in the form of elongated ellipsoidsor other shaped recesses that extend only partially through the stent atvarious depths rather than as cutouts which extend all the way throughthe stent. Furthermore, the stent may have some combination of cut-outregions and recesses.

Further to the present invention, cut-out regions or shaped recesses maybe provided in all of the turns of the serpentine portions of the stent,as shown in FIG. 6 a, or in only some of the turns of the serpentineportions. An example of a stent having serpentine portion with cut-outregions or shaped recesses in less than all of the turns is shown inFIG. 24.

In the stent of FIG. 24, the cut-out regions are disposed to facilitateopening of the proximal and distal ends of the stent first, while theelongated ellipsoid recesses are disposed to act as a reservoir forholding a substance such as a drug which is to be delivered to a targetlocation in the body. The serpentine portions in the proximal end of thestent have cut-out regions or shaped recesses 30 in the proximal turnsof the serpentines and the serpentine portions in the distal end of thestent have cut-out regions or shaped recesses 30 in the distal turns ofthe serpentines. Another embodiment of the invention in which theserpentine portions in the proximal end of the stent have cut-outregions 116 or shaped recesses 30 in the distal turns of the serpentinesand the serpentine portions in the distal end of the stent have cut-outregions 116 or shaped recesses 30 in the proximal turns of theserpentines is shown in FIG. 25. If the stent as shown in FIG. 25 hascut-outs 116 rather than shaped recesses 30, it will open in the centerprior to opening in the ends. More generally, individual serpentineportions of the stent may be provided with cut-out regions exclusivelyin the distal end of the serpentine or the proximal end of theserpentine to tailor the properties of the stent, depending on theopening properties desired, and whether or not the stent is also beingemployed for drug delivery.

It is also within the scope of the invention for adjacent cut-outs orshaped recesses to be spaced further apart along the serpentine portion.For example cut-out regions 116 or shaped recesses 30 may be provided atevery third or fourth turn or may be spaced further apart.

It is further within the scope of the invention for adjacent pairs ofcut-outs 116 or shaped recesses 30 to be spaced further apart along theserpentine portion. For example, as shown in FIG. 26, every other pairof turns 105 are provided with cut-out regions 116 or shaped recesses30. Adjacent pairs of cut-out regions or shaped recesses may also bespaced further apart from one another along the serpentine portion 104of stent 100. Other spacings of cut-out regions or shaped recesses arealso within the scope of the invention.

It is also within the scope of the present invention, to replace anyshaped recess with a shaped recess of a different shape. Varying thequantity, size, i.e. length and width, as well as the depth of theshaped recess may be employed to control the amount of a substance whichwill be deposited upon deployment of the stent.

More generally, it is within the scope of the invention to providecut-out regions, elongated ellipsoids or other shaped recessesexclusively in some or all of the turns of the proximal and/or distalserpentine portions of the stent. The number of cut-out regions orshaped recesses in the inventive stents may be varied along the lengthof the stent, both in the on the struts and curved sections of thestent, and in turns of the serpentines may also be varied along thelength of the stent.

In the case of a low opening pressure stent, the number of cut-outregions in the serpentine portions may decrease from the proximal and/ordistal ends of the stent to the middle of the stent. Less pressure isrequired to expand those portions of the stent having more cut-outregions. This feature may provide desirable where a retaining sleeve isdisposed about the proximal and/or distal ends of the stent.

To that end, the invention is also directed to stents having endserpentine portion(s) at the proximal and/or distal ends of the stentand intermediate serpentine portions between the end serpentine, whereone or both of the end serpentine portions have more cut-out regions,elongated ellipsoids or other shaped recesses than the intermediateserpentine portions. Such as stent is shown by way of example in FIG. 11a or 11 d. In the stent of FIG. 11 a, the intermediate serpentineportions do not have any cut-out regions, elongated ellipsoids or othershaped recesses. Desirably, one or both of the end portions require lesspressure to expand than the intermediate portions.

The invention is also directed to stents having end serpentineportion(s) at the proximal and/or distal ends of the stent andintermediate serpentine portions between the end serpentine, where oneor both of the end serpentine portions have larger cut-out regions,elongated ellipsoids or other shaped recesses than the intermediateserpentine portions. Desirably, in the case of cut-out regions, one orboth of the end portions require less pressure to expand than theintermediate portions.

The invention also is directed to embodiments in which the cut-outregions are designed and distributed such that the middle portion of thestent opens prior to one or both of the proximal and distal ends of thestent. For example, the middle portion of the stent may have morecut-out regions than one or both ends of the stent or may be providedwith larger cut-out regions than one or both ends of the stent. Anexample of such a stent is shown in FIG. 11 b. The stent of FIG. 11 bhas cut-outs only in the middle serpentine.

The cut-outs regions as described in the paragraph above, may bereplaced with shaped recesses rather than cut-out regions for drugdelivery, an example of which is shown in FIG. 11 e. Of course, thesubstantially circular shaped recesses may be replaced with othergeometric shapes including elongated ellipsoids, for example, as well.

The number of cut-out regions may also be adjusted to allow forincreased stent securement in desired areas of the stent. Specifically,in the case of a balloon expandable stent, those regions of a stentlacking cut-out regions will typically have increased securement to aballoon catheter when crimped on a balloon and catheter than regionshaving cut-outs.

The cut-out regions that are provided in the turns of the inventivestents allow the turns of the stent to open more easily when a givenforce is applied thereto, thus facilitating expansion of the stent. Thisin turn, allows for wider struts to be employed, thereby increasing theradiopacity of the stent.

The invention is also directed to a radially expandable stent comprisinga plurality of serpentine portions extending about the circumference ofthe stent, each serpentine portion having a plurality of turns where atleast some of the turns and/or struts of the serpentine portions have atleast some shaped recesses or wherein at least some of the turns have atleast some fully enclosed cut-out regions and shaped recesses extendingtherethrough, or at least some of the turns have fully enclosed cut-outregions extending therethrough and some of the struts have at least someshaped recesses.

The shaped recesses are distributed about the stent so as to achieveoptimum delivery of a drug upon deployment of the stent.

The cut-out regions may be distributed about the stent so that the stentopens in a non-uniform manner. Desirably, the stent includes a proximalserpentine portion at a proximal end of the stent, a distal serpentineportion at a distal end of the stent and a middle portion disposedbetween the proximal and distal ends of the stent and the cut-outregions are distributed such that the proximal and distal ends of thestent open prior to the middle portion of the stent. The cut-out regionsmay also be distributed such that the middle portion of the stent opensprior to one or both ends of the stent. Also desirably, the cut-outregions are substantially arcuate prior to expansion of the stent.

The invention is further directed to a stent such as that shown in FIG.24 and many of the other figures disclosed herein comprising at leastone tubular serpentine member 104 having a first end and a second end.The serpentine member has a plurality of turns 105 at the first end anda plurality of turns at the second end. Each of the turns at the firstand second ends have a fully enclosed cut-out region extendingtherethrough, or elongated ellipsoid or other shaped recess 30.Typically, the stent will comprise a plurality of tubular serpentinemembers with adjacent tubular serpentine members connected one to theother. Desirably, the shape of the fully enclosed cut-out regions,elongated ellipsoid or some such other shaped recess is characterized bya first area when the stent is in an unexpanded configuration and by asecond area when the stent is in an expanded configuration, the secondarea larger than the first area. The inventive stents may also beprovided in embodiments in which the fully enclosed cut-out regions, orshaped recessed are characterized by a first width when the stent is inan unexpanded configuration and by a second width when the stent is inan expanded configuration, the second width greater than the firstwidth. Typically, the cut-out regions, or other shaped recesses of theinventive stent will be arcuate when the stent is in the unexpandedstate although cut-out regions or shaped recessed of other shapes asdescribed above are also disclosed herein.

The inventive stents disclosed herein may be made of any suitable stentmaterial including metals and polymeric materials as are known in theart. Suitable metals include stainless steels, tantalum, titanium,nitinol, Elgiloy and MP35N. Portions or the entirety of the inventivestents may be radiopaque. For example, a gold coating may be provided toselected regions or the entirety of the inventive stents.

The inventive stents may be laser cut, chemically etched,electrodischarge machined or cut using any other suitable technique froma tube. The stent pattern may also be cut into a sheet using any of theabove-mentioned techniques or any other suitable technique, the sheetrolled into tubular form and the ends welded or otherwise joinedtogether. The inventive stent designs may also be used in coiled sheetstents where the sheet which forms the stent is formed into a roll whichmay unroll to a wider opening.

It is further within the scope of the invention for the inventive stentsdisclosed herein to be provided with biocompatible coatings such aslubricious coating or other types of coatings known to those of skill inthe art.

The entirety of the stent may be coated with the therapeutic agent, thecut-out regions only may be provided with the therapeutic agent, or theshaped recesses may be provided with the therapeutic agent, or somecombination thereof. In one embodiment, one or more of the shapedrecesses and/or cut-out regions will be filled with a therapeutic agent.It is also within the scope of the invention for only shaped recesses tobe filled with a therapeutic agent. Moreover, in some embodiments of theinvention, it may be desirable to have shaped recesses and/or cut-outregions including a therapeutic agent in one portion of the stent andcut-out regions without a therapeutic agent in another portion of thestent. For example, the shaped recesses and/or cut-out regions at one orboth ends of the stent may include a therapeutic agent, and the cut-outregions in the middle of the stent may lack a therapeutic agent. Asanother example, the shaped recesses and/or cut-out regions in themiddle of the stent may include a therapeutic agent and the cut-outregions in the ends of the stent may lack the agent. The shaped recessesand/or cut-out regions may be selectively filled by masking otherportions of the stent and spraying, dipping or otherwise disposingtherapeutic agent only in the shaped recesses or cut-out regions. Forexample, the stent may be placed on a mandril and masked so that thetherapeutic agent may be disposed only in desired shaped recesses and/orcut-out regions of the stent.

In some embodiments of the present invention, it is desirable to provideonly shaped recesses on the stent which are to be selectively filledwith a therapeutic agent. The stent may optionally include cut-outregions to facilitate opening of the stent, but which do not have anytherapeutic agent therein.

The inventive stents disclosed herein may be used in any suitable bodilyvessel including the coronary arteries, the peripheral arteries,arteries of the neck, cerebral arteries, veins, biliary ducts, urethras,ureters, fallopian tubes, bronchial tubes, the trachea, the esophagusand the prostate. Its uses include supporting vessels in the region oflesions and vessels in the region of aneurisms. It is also particularlysuited for use as an intracranial stent.

The invention is also directed to the combination of a inventive stentdisclosed herein and a delivery catheter where a retaining sleeve isdisposed about the proximal and/or distal end of the stent, as shown byway of example in FIG. 27. Catheter 200 includes stent 100 disposedabout balloon 208 and catheter member 202. Retaining sleeves 204 areprovided at the proximal and/or distal ends of the stent.

In one embodiment, stent 100 desirably has few and/or larger cut-outregions at the proximal and/or distal end to accommodate the additionalforce that is required to expand the stent in the region of theretaining sleeve.

The above disclosure is intended to be illustrative and not exhaustive.This description will suggest many variations and alternatives to one ofordinary skill in this art. All these alternatives and variations areintended to be included within the scope of the claims where the term“comprising” means “including, but not limited to”. Those familiar withthe art may recognize other equivalents to the specific embodimentsdescribed herein which equivalents are also intended to be encompassedby the claims.

Further, the particular features presented in the dependent claims canbe combined with each other in other manners within the scope of theinvention such that the invention should be recognized as alsospecifically directed to other embodiments having any other possiblecombination of the features of the dependent claims. For instance, forpurposes of claim publication, any dependent claim which follows shouldbe taken as alternatively written in a multiple dependent form from allprior claims which possess all antecedents referenced in such dependentclaim if such multiple dependent format is an accepted format within thejurisdiction (e.g. each claim depending directly from claim 1 should bealternatively taken as depending from all previous claims). Injurisdictions where multiple dependent claim formats are restricted, thefollowing dependent claims should each be also taken as alternativelywritten in each singly dependent claim format which creates a dependencyfrom a prior antecedent-possessing claim other than the specific claimlisted in such dependent claim below (e.g. claim 3 may be taken asalternatively dependent from claim 1 or claim 2; claim 4 may be taken asalternatively dependent from claim 1 or any of claims 2–3; claim 5 maybe taken as alternatively dependent from claim 1 or any of claims 2–4;etc.).

This completes the description of the preferred and alternateembodiments of the invention. Those skilled in the art may recognizeother equivalents to the specific embodiment described herein whichequivalents are intended to be encompassed by the claims attachedhereto.

1. A stent comprising a first strut having a first side and a secondside, each side having alternating crests and troughs wherein the crestsof said first side of said first strut align with the troughs of saidsecond side of said first strut, said first strut having a second strutadjacent said first strut, having a first side and a second side, eachside having alternating crests and troughs wherein the crests of saidfirst side of said second strut align with said troughs of said secondside of said second strut, and said crests of said first side of saidfirst strut align with said crests of said second side of said secondstrut and said troughs of said first side of said first strut align withsaid troughs of said second side of said second strut, the stent furthercomprising at least one turn having at least one shaped recess.
 2. Thestent of claim 1 wherein said first strut has a wave-like pattern. 3.The stent of claim 1 wherein said second strut has a wave-like pattern.4. The stent of claim 1 having at least one shaped recess locatedbetween at least one crest and trough of said first strut.
 5. The stentof claim 1 having at least one shaped recess located between a crest anda trough of said first strut and at least one shaped recess locatedbetween a crest and a trough of said second strut.
 6. The stent of claim1 wherein said at least one shaped recess is an elongated ellipsoid. 7.The stent of claim 1 wherein said at least one shaped recess has asubstantially circular shape.
 8. The stent of claim 1 wherein said atleast one shaped recess contains a therapeutic agent.
 9. The stent ofclaim 8 wherein said therapeutic agent is selected from the groupconsisting of genetic material, growth factors, antineoplastics,antimitotics, anti-inflammatories, antiplatelets, anticoagulants,antifibrins, antithrombins, antiproliferatives, antibiotics,antioxidants, and antiallergenic substances.
 10. The stent of claim 5wherein the recess located between the crest and trough of said firststrut and the recess located between the crest and trough of said secondstrut both contain a therapeutic agent.
 11. The stent of claim 1 whereina plurality of said struts have a plurality of shaped recesses thereon,and a plurality of turns have a plurality of shaped recesses thereon.12. The stent of claim 1 having a plurality of shaped recesses havingsubstantially circular and ellipsoid shapes.
 13. The stent of claim 1wherein at least one strut has more than one shaped recess thereon.